I was nervous buying the cheaper tray, but I typically have had pretty good luck with Fellowes products. The tray is well-built, the mechanisms are sturdy and of good quality. It's stable enough to hold my wrists (even when resting them... heavily).
The only drawbacks (and I'm not lowering the stars for this because I tend to be pickier than most): the mouse area needs an actual mouse pad instead of the textured surface and the tension knob is in an awkward spot.
Otherwise, this is nice and wide enough to hold the keyboard (although I'm using a smaller Apple keyboard with 10-key, it's close to the size of a standard PC keyboard) and the mouse. And the wrist pads that come with it are nice and sturdy, they're not quitters so they should hold up for some time (but easily removable if you want to swap them out).
I would buy this again if I had to.